HELP! Lumia 1520 Camera is not working (Blank Screen)

My Lumia 1520 Camera gives me blank screen with whatever app I tried. Practivcally the cam is unusable right now.
I am so freaked out right now..

Happened to me just an hour ago.
I was taking a picture successfully in 5MP via Nokia Camera using manual mode for exposure time + WB fluorescent. Then I went to cam setting to change to bigger resolution/MP. In the cam setting page, accidentally I pressed HOME button. I press BACK button to get back to previous setting page... and saw "Loading....." endlessly.
Hit HOME after minutes. I Tapped Nokia Camera Tile in start screen. But all I got is blank, black, screen and nothing I can do.

Uninstalled Nokia Camera
Reinstalled.
Not working.
I reset camera (setting/application/photo)
I soft reset phone; Power+VolDown (with exclamation symbol on the start)
Still Not working

UPDATE1:
I'm Resetting my phone now via Reset Phone in the Setting on phone. After Reset, Nokia Camera back to Nokia Pro Camera (old version). It is now restoring my backups (downloading/installing apps). Nokia Camera is queued. I tried using Nokia Pro Camera, the blank screen persists! >.< I guess I'll wait until Nokia Camera installation finished then I'll give it another try.

UPDATE2:
Reset Phone is not working. I installed Nokia Camera over Nokia Pro Camera. But, still...BLANK!
I am now using Recovery Tool from Nokia. Finished the steps. Check Camera. Still.... BLANK!!
This is serious!

UPDATE4:
Windows Phone 8.1 is installed now on my lumia 1520. Camera blank screen problem still persists. I give up. I guess it's definetely a hardware problem. Time to visit Nokia Care Center. I hope they give me a new one.

UPDATE5:
Went to NCC yesterday noon. They said I have to left my unit there with them to check. They will go with the software first then proceed to hardware service/investigation if it wasnt software related. Today they will give me the result news. I'm very skeptic now if it was the software. If its hardware they better give me a new unit. Well, Wish me luck.

UPDATE6: 06-13-2014 at 01:36 AM
Yesterday local NCC said they gave up (said it is now beyond their capability) and have to send my 1520 to the the central NCC for further investigation/repair that will take about (OMG!) 3 weeks???? >.<

UPDATE7: 25 June 2014
This morning I had an SMS from Nokia told me that my 1520 is ready to be picked up.
With big grin I ran quick to local NCC! Long time no see my dear bandit.
I spend about 30 minnutes there just to test the Camera. Nokia replace the camera unit because of the dead unit. The Camera seems ok... working fine as far as I checked. And the rapair/camera unit is free of charges!! Kudos to Nokia for this!
BUT... I notice that Nokia repair quality is in question. Camera module was not correctly placed inside (not centered) the round glass of the housing. I wonder if it will impair the mechanism of the camera (with the optical stability or focusing). But sure as hell its annoying and unacceptable... it's not right.. even by Nokia's design standard (with everything layed-out centered in the front and back).
Plus.. the Rubber seal/gasket that keep the glass tight with housing in the front is damaged/dented in two places (top right & left center).

I will not accept this because my device is practically new (less than a month), mint condition, with light use.
I ask my local NCC to bring it back to central NCC to fix. And I want new rubber front gasket (since they will disassemble again and will surely leave their marks like before).
I want my new device in its new condition. Not like that is had been repaired with broken gasket here and there and not perfectly centered camera module (gosh its annoying just remembering it) >.<

Initially local NCC would make me a new repair order. means.. my 1520 will have to get in normal queue and I will spend approximate time like before. After sometimes negotiating, they give me back my last repair order and decided to give additional complaint/notes in the repair order so this will be a repair in progress.. not a new one. And HOPEFULLY it will take shorter time to fix compare to last time.

Well, here I am. Waiting again for my lumia 1520. Pray with me that it will come nice, fixed, and like totally brand new! Amen!

UPDATE 8: Finale

Four days ago (july4th), I picked up my Lumia 1520 from NCC Mampang after received an SMS from Nokia.
I spent minutes to inspect and testing my phone there.
-Damaged gasket fixed (they didn't replaced it w/ new one but managed to make it smooth enough).
-Camera placement, centered.
-Camera is working (from previous replacement)
-Other functions are checked and working (speaker, call, wifi, data connection, charging,etc.)
-SDCARD door is a bit misaligned and not properly fixed into the housing (a bit protrude compare to SIM door). I can see it and feel it with my fingertip. I just realized this when I already took it home and easily fixed by opening the SDCARD & SIM door then correcting the position (using my nail) of square (thick) sticker to properly fit the concave/frame and pressed it inside. Assembled the doors, and now it's more flushed out fine.

Repair is free-of-charge :) Kudos Nokia!
Well, now i have a big grin on my face since my beautiful 1520 is alive and kicking. :D
Eventho I'm starting to to forget about the waiting, non-responsive hot-line NCC Mampang (several occasions when I called the number 10-20 times with nobody pick-up/answer, and previous repair quality, I hope Nokia/Microsoft can work up on their standard in service quality. Amen.

My 1520 had the same problem. The physical button had stopped working then the phone froze . I did a hard or soft reset , I'm not sure I held down the volume up volume down and the power button for at least 30 seconds , then it vibrated and shut down then it restarted. Since then the camera button has started to work once more. The phone seems fine now